Cam locked release mechanism

ABSTRACT

THIS INVENTION RELATES TO A SPRING LOADED CAM LOCKED RELEASE MECHANISM USED FOR FIRE EXTINGUISHERS. THE MECHANISM COMPRISES A SPRING LOADED CAM PLATE HAVING AN ACTUATING BOLT FIXED THERETO AND ADAPTED TO UNSEAT A VALVE ON A FIRE EXTINGUISHER, A RELEASE BAR HAVING A STUD ON THE TOP THEREOF FOR ABUTMENT AND A PAIR OF SPACEDAPART INTEGRAL INCLINED SLOPE CAMS THEREBELOW UPON WHICH SLOPES SAID CAM PLATE RESTS WHEN IN COCKED POSITION, A GUIDE PLATE DISPOSED IN A CO-ACTING CHANNEL IN SAID CAM PLATE FOR HOLDING SAID CAM PLATE IN HORIZONTAL POSITION AT ALL TIMES DURING VERTICAL MOVEMENT THEREOF, AND A CABLE RETAINER BAR SECURED SWINGABLY TO A TENSIONED STEEL CABLE HAVING A FUSIBLE LINK AND ALSO SECURED LOOSELY TO A HAND PULL CABLE FOR VERTICAL MOVEMENT OF SAID CABLE RETAINER OVER SAID STUD OF SAID RELEASE WHEREBY MOVEMENT OF SAID CABLE RETAINER EFFECTS RELEASE OF SAID RELEASE BAR TO PERMIT SAID CAM PLATE TO MOVE DOWNWARDLY UNDER SPRING PRESSURE ON SAID CAM SLOPES THEREBY ALLOWING SAID ACTUATING BOLT TO STRIKE A RELEASE PIN TO UNSEAT THE VALVE ON A FIRE EXTINGUISHER.

Oct. 19, 1971 R. R. CHOLIN ETAL 3,613,461

CAM LOCKED RELEASE MECHANISM Filed Jan. 27, 1970 A L M u M XNK United States Patent U.S. Cl. 742 3 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a spring loaded cam locked release mechanism used for fire extinguishers. The mechanism comprises a spring loaded cam plate having an actuating bolt fixed thereto and adapted to unseat a valve on a fire extinguisher; a release bar having a stud on the top thereof for abutment and a pair of spacedapart integral inclined slope cams therebelow upon which slopes said cam plate rests when in cocked position; a guide plate disposed in a co-acting channel in said cam plate for holding said cam plate in horizontal position at all times during vertical movement thereof; and a cable retainer bar secured swingably to a tensioned steel cable having a fusible link and also secured loosely to a hand pull cable for vertical movement of said cable retainer over said stud of said release whereby movement of said cable retainer effects release of said release bar to permit said cam plate to move downwardly under spring pressure on said cam slopes thereby allowing said actuating bolt to strike a release pin to unseat the valve on a fire extinguisher.

It is an object of this invention to provide a spring loaded cam biased strike bolt to be actuated by hand operation or alternately by release of tension of a tensioned steel cable having a fusible link therein.

It is another object to provide a cocked release mechanism of minimum parts and of foolproof operation and adapted for fire extinguishers.

These and other objects of this invention will become apparent upon reading the following disclosure of an illustrative embodiment thereof in which FIG. 1 is a side view of the mechanism shown in cocked position,

FIG. 2 is a front view of the mechanism shown in cocked position, and

FIG. 3 is a detail view of the manner of operation of the cam plate with its fixed bolt upon release of the cam plate from its captively held position,

FIG. 4 is a top view of the cam plate showing the channels therein.

Turning to the drawing, a vertical standard is provided with a top fixed plate 11 having an aperture 12 therein for passage of a hand release cable 13. The fire code of some communities require automatic fusible link actuated fire extinguishers to be also operable by hand release cable.

The mechanism of this invention, secured to the standard 10, comprises five indispensable pieces with an ancillary horizontal double-shelf support structure 14 secured by a pair of bolts 15 to standard 10. The double shelf 14 is preferably of integral construction and comprises a top apertured shelf 16, a bottom apertured aligned shelf 17, an integral front wall 18 having a fixed pivot pin 19 therein, and a vertically disposed integral flange 20 having a pair of apertures therein for securing bolts 15.

In the aligned apertures of suitable diameter of shelves 1'6 and 17, there is disposed a valve release actuating bolt 21 having a bolt head 22. A suitable compression spring 23 is disposed against the bolt head 22 and the ice plate 16. Upon release of the compressed spring 23, the bolt head 22 strikes the valve release pin 24 forcing it downwardly to open the valve 25 of the fire extinguisher 26 to permit the fire extinguishing chemicals therein to be conducted by conduit 27 to the fire.

A fundamental feature of this invention lies in the cam locked elements which is cocked by handle 30, and used to compress spring 23 against the shelf 16 by rotation on pivot pin 19. A pull out pin 31 is provided to remove handle 30 after cocking the mechanism.

There are four fundamental working parts to this invention, namely, the cam plate 40, a release bar 50', a guide bar 60 and a cable retainer bar 70. The bolt 21 is threaded into a co-acting threaded aperture in the cam plate so as to be substantially an integral part thereof.

The cam plate is provided with a channel 41 for the guide bar 60 and with a unique setback channel 42 having a pair of opposed setback ledges 43, each having an edge 44 adapted to be slidingly disposed upon a cam slope 51 of a respective triangular cam 52 of a pair of cams 52, disposed respectively on each side of the release bar 50. Thus the edges 44 of the ledges 43 are disposed on the slopes 51 of the earns 52 when the mechanism is in cocked or operable position.

The release bar 50 is provided at its top end with an abutment 53 against which the cable retainer 70 is urgingly pulled by a tensioned cable 13X having a fusible link therein. The release bar 50 is further provided at its bottom end with a sloped wall 54 in which is threaded a cavity to receive bolt 55, disposed loosely and swingably in a suitably large aperture in fixed ledge 16. Thus the release bar 50 is swingably and captively held to the ledge 16.

The guide bar 60 is secured to the flange 20 by the bolts 15 and is disposed in channel 41 of the cam plate 40. Guide bar 60 is provided with a top surface 61 having a threaded cavity to receive a spring loaded bolt 62.

The cable retainer 70 is adapted to be released upwardly by hand operation of cable 13 when the retainer bar 70 is pulled above the abutment 53. This cable retainer bar is also adapted for operation by being pushed sidewardly by abutment 53 when the fusible link in the tensioned cable 13X is relieved of pull tension on the retainer bar 70 as by the melting of the link in the cable.

The cable retainer bar 70 is provided with communicating top and side aperture 71, having a front communicating threaded aperture adapted to receive a locking set-screw 72. Thus cables 13 and 13X are locked by setscrew 72. Cable 13 may be integral with cable 13X and may be otherwise secured to the retainer bar 70 then by means of a set-screw. The rear edge of the retainer bar is disposed on the slope 61 of the guide bar 60 and functions as a fulcrum when the retainer bar is hand operated by cable 13.

The cam plate 40 is cocked or disposed in spring 23 loaded operation by the upward pivoting of handle 30, thereby compressing spring 23 against ledge 17 (FIG. 2) with raising of the cam plate 40 to effect a resting of cam plate edges 44 of the ledges 43 on the slopes 51 of the opposing cams 52 with pulling of the release bar 50 furthermost leftwardly to tension cable 13X and its fusible link against the abutment 53 and thereafter securing the tensioned cable 13X at its fusible link end. The so cocked or tensioned by cable 13X mechanism may be untensioned or operated by release of the cable tension as by the melting of the fusible link and alternately it may be operated by hand pulling of cable 13.

After cocking the mechanism by handle 30, the handle 30 is removed as the mechanism remains in cocked position due to the tensioned cable 13X. FIG. 3 shows operation by hand pulling of cable 13 so as to pull the retainer bar 70 above the release abutment 53.

In either manner of operation, the cam plate and its bolt 21 is pushed forcefully downwardly by the large compressed spring 23 with pushing away of the release bar 50 by the action of the cam plate edges 44 on the cam slopes 51 of cams 52 of the release bar 50. The result is that bolt 21 is propelled forcefully against the release pin 24 of the valve 25 thereby opening the valve 25 to permit fire extinguishing chemicals under pressurized gas in tank 26 to be conveyed by conduit 27 to the source of the fire.

This invention as above described relates to pressurized chemical fire fighting apparatus operated by a springloaded, cable-tensioned, cam-biased mechanism having a fusible link in said tensioned cable, said mechanism being adapted for alternate operation by means of a non-tensioned hand cable.

We claim:

1. A cam-biased, spring-loaded, tensioned-cable retained mechanism for actuating chemical fire fighting apparatus comprising a frame support having a shelf thereon; a cam plate having a guide bar channel at one end and a release bar channel at an adjacent side; a headed bolt means having a captively held compression spring disposed thereon, said bolt being fixedly secured to said cam plate extending therebelow in spaced relationship to a valve release pin, said spring being selectively compressed by being biased against said support shelf; a guide bar having a sloped top end disposed in said cam plate co-acting channel and secured vertically to said support; a release bar having a pair of adjacent sloped earns, a top wall having an abutment thereon for engaging said guide bar and a bottom angular wall swingably secured to said support shelf; a cable retainer bar spring loadedly secured to said top sloped end of said guide bar and normally biased against said abutment of said release bar, said retainer bar having aperture means for fixedly securing a tensioned fusible link cable and also a nontensioned hand pull cable; and handle means pivotally secured to said frame for elevating said cam plate with compression of said compression spring with simultaneous cocked emplacement of said cam plate on said sloped cams of said release bar whereby cable release of said cable retainer bar against the abutment of said release bar permits said compression spring to propel said cam plate bolt against said valve release pin of a pressurized container of fire fighting chemicals with simultaneous pushing away of said release bar by sliding motion of said cam plate on the cam slopes of said release bar.

2. The mechanism of claim 1 wherein said opposed cams of said release bar are of triangular configuration.

3. The mechanism of claim 2 wherein said aperture means for fixedly securing said cables comprises a threaded aperture and set screw means for lockingly engaging said cables.

Refcrences Cited UNITED STATES PATENTS 1,722,754 7/1929 Knauf 25174 2,008,961 7/1935 Lessard 13772 2,287,989 6/1942 Grifiith 74-2 3,017,776 3/1966 Roby 74-2 WILLIAM F. ODEA, Primary Examiner T. R. HAMPSHIRE, Assistant Examiner US. Cl. X.R. 16919, 21 

